Field of the Invention
The present invention relates to a power transmission system for a hybrid electric vehicle, and more particularly, to a power transmission system for a hybrid electric vehicle, which is configured for preventing damage to a one-way clutch caused by torque vibration properties of an engine, and reducing drag and a size of a planetary gear set by supporting inner sides of a planet carrier and a ring gear.
Description of Related Art
An environmentally-friendly technology of vehicles is a key technology that dictates the survival of the future vehicle industry, and advanced vehicle manufactures have a great effort to develop environmentally-friendly vehicles in order to meet regulations associated with environments and fuel economy.
Therefore, the vehicle manufactures have developed future vehicle technologies such as electric vehicles (EV), hybrid electric vehicles (HEV), and fuel cell electric vehicles (FCEV).
Because the future vehicle has various technical limitations in respect to weights and costs, the vehicle manufacturers have focused on the hybrid electric vehicle as an alternative for meeting emission regulations, and improving fuel economy performance, thereby solving practical problems, but face fierce competition in order to commercialize the hybrid electric vehicle.
The hybrid electric vehicle refers to a vehicle that uses two or more power sources, and a gasoline engine or a diesel engine which uses the existing fossil fuel and a motor/generator which is operated by electrical energy are used as the power sources.
At a low speed, the hybrid electric vehicle uses the motor/generator, as a main power source, which has relatively good low-speed torque characteristics, and at a high speed, the hybrid electric vehicle uses the engine, as a main power source, which has relatively good high-speed torque characteristics.
Therefore, in a low-speed section, the engine, which uses fossil fuel, stops operating, and the motor/generator is used, as a result, the hybrid electric vehicle has excellent effects of improving fuel economy and reducing emission of exhaust gas.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.